Exhaust steam injector control system



y 30, 93 J. F. GRIFFIN ET AL 1,912,192

EXHAUST STEAM INJECTOR CONTROL SYSTEM Filed April l6, 1929 2 Sheets-Sheet l By a/%@ A TTORNE Y.

ay 30, 1933. .1. F. GRIFFIN ET AL 1,912,192

, EXHAUST STEAM INJECTOR CONTROL SYSTEM Filed April 16, 1929. 2 Sheets-.Shet 2 Fig 4 "til" 0 .22

- INVENTOR. O /4r-/%or MYfiams o Y Patented May 30, 1933 Fri JOSEYPE 1i. GRIFFIN, OF TEANEGK, NEW TEE- Y, AND ARTH'L T- VTELLIAMS, OF YOB-K, N. Y., ASSIGNQFZS TO THE SUPERHE CQZZIEANY, F HEY] YORK, N. Y.

EXHAUST STEAM INJEG'ZGR CONTROL SYSTEM Application filed April 18,

This invention relates to control systems for exhaust steam injectors of the general type disclosed in United States Letters Patent 1,342,128 granted June 1, 1920, to 5. Metcalfe et al.

The principal purpose of the invention is the provision of an improved form of control system governing the admission of live steam to the injector during periods when exhaust steam is not available.

The more specific features and details of the invention together with the advantages to be derived from its use may best be understood from a consideration of the ensuing description of preferred embodiments thereof, taken in conjunction with the accompanying drawings in which Fig. 1 is a diagrammatic view partly in section of an injector and control system embodying the invention; Fig. 2 is an enlarged detail section of a valve arrangement included in the control system, Fig. 3 is a similar view of another such valve; Fig. 4 is a view similar to Fig. 1 showing a modified form of control system; and Figs. 5 and 6 are enlarged sections of valve arrangements shown in Fig. 4.

in injector control systems of tie general type to which the present invention relates, the control of live steam admission to the injector during periods when exhaust steam is not available has been efiected through utilization of pressure taken from the steam chests of the engine supplying exhaust steam to the injector. The arrangement in these systems is such that when steam chest pressure fails a suitable'valve is opened by the releasing of this pressure to admit live steam to the injector to replace the no longer available exhaust steam, and when steam chest pressure is built up the reverse action takes place.

In the application of such control systems to locomotive engines where injectors of the type under consideration have their great est application, this system of controlhas developed an undesirable weakness due to the fact that under certain locomotive operating conditions suflicient steam pressure is built up in the steam chests of the engine 1929. Serial No. 355,631.

to cause the live steam supply to the injector to becut off, while at the same time the load on the locomotive is such that this steam chest pressure is not sufficient to start-the engine and provide the exhaust steam necessary to take the place of the live steam sup: ply which has been cut oif. Under such con ditions therefore it is possible, when the in? jector is operating under live steam with the engine at rest, to cause the injector to fail in operation if the engine throttle is open without causing actual starting of the locomotive engine. The same condition also occurs upon the admission of drifting steam to the engine, such steam acting to produce a steam chest pressure sufiicient to shift the injector to exhaust steam operation but not supplying sufficient exhaust steam to enable the inj ect-or to function.

The present invention overcomes this objection in prior control systems by utilizing the motion of the engine throttle rigging. to control the admission of l ve steanrtothe injector so that an amount of steam sufi icient to insure an adequate supply of exhaust steam under all normal circumstances must be admitted to the engine before the live steam supply is shutofi'.

One manner in which the invention may be carried into eli'ect is shown in Fig. 1 in which the injector A is shown, as comprising acasing 1 carrying the usual exhaust steam nozale 2, water cone 3, secondary steam nozzle 4 and combining tube 5, the latter delivering to a delivery tube not shown. Water is sup plied to the injector from inlet 6 controlled by valve 7, the latter being opened against spring pressure by the pressure of steam admitted to piston 8 through the connection 9. The main low pressure steam chamber-1O f the injector is supplied with exhaust steam through an inlet controlled by the exhaust valve 11, the valve being normally held in closed position by spring 11a and opened by the pressure of a supply of control steam admitted through conduit 12 to piston 13. The main live steam supply to the injector is taken from a suitable source such as the boiler turret through the supply pipe 14 and the operation of the injector iscontrolled through the manually operated valve located in this conduit.

High pressure live steam delivered by the pipe 14 flows from the passage 16 to the high pressure steam nozzle 17 This nozzle supplies high pressure live steam to the in ector at all times when the latter is in operation, and such steam will hereinafter be referred to as supplementary steam. Live steam admitted to the injector to take the place of eX- haust steam when the latter is not available enters the injector through the passage 18 and flows to the chamber 10 by way of ports 19. This live steam, to be hereinafter referred to as auxiliary steam, is controlled through the medium of an automatic valve 20, having a double seated head. which when in the lower position of the valve serves to prevent steam from entering passage 18, and which in its upper position opens this passage and seats to prevent the passage of live steam to chamber 21 above the valve. In this chamber is located spring 22, the purpose of which will appear later. Auxiliary steam reaches the chamber surrounding valve 20 through the restricted opening or port 23, which serves to reduce the pressure of this steam when valve 20 is open and steam is flowing from pipe 14 to the passage 18.

Steam from passage 16 passes by way of p0rt24 to the connection 9 so that the water valve 7 is open at all times when supplementary steam is being admitted to the in jector.

Live steam is taken from the supply pipe 14 through the conduit to the chamber 21 above valve 20 and it is to be noted that the conduit 12 leading to the exhaust valve piston 13 also communicates with this chamber.

Valves 20 and 11, operate in alternation to admit either exhaust steam or auxiliary live steam in accordance with engine working conditions, and this operation of these valves is controlled through the admission of live steam through conduit 25 to the chamber 21, or the venting of the latter to atmosphere or other zone of low pressure. If steam pressure is not present in chamber 21 the exhaust valve will be closed by spring 12a and'the automatic valve 20 will be moved to its upper position because of the pressure exerted by steam admitted through port 23, the difference in area between the seat 20a and the piston 20b being sufficient to cause an unbalanced pressure capable of lifting the valve against the action of spring 22. However. with the valve once seated in its upper position, the flow of steam through port 23 causes a drop in pressure of the steam acting on the valve, so that the admission of high pressure live steam through conduit 25 to chamber 21 acts to move the valve to its lower seat and shut off the supply of auxiliary steam. At the same time admission of this high pressure steam to chamber 21 causes steam to be admitted to the piston 13 through conduit 12, thereby opening valve 11 to admit steam to the injector.

Control of the admission of live steam to the valve chamber 21 is effected by means of a pilot valve B interposed in conduit 25. The pilot valve comprises a. housing 26 forming a chamber 27 into which one branch of conduit is connected and an outlet chamber 28 connected by means of the other branch of conduit 25 to chamber 21. Chambers 27 and 28 are placed in communication through a port controlled by a valve member 29 having a head 29a adapted to seat over the connecting port. Chamber 28 is placed in communication with the atmosphere through a port which controlled by an oppositely dirooted valv, head 29?), the two valves being so arranged that they seat alternately upon movement of the valve member 29. As will be clear from Fig. 3, when the valve member 29 is in the position shown steam will be prevented from passing to chamber 21, and the latter Wili be vented to atmosphere by way of chamber 28 and the passages formed in the stem of the valve member 29. Upon movement of valve member29 to its upper position the vent to atmosphere will be closed by valve 297) and communication will be established between the steam pipe 14 and chamber 21 through the opening of valve 29a.

The position of valve member 29 is controlled by the engine throttle operating mechanism which has been shown in Fig. 1 as of the conventional type comprising a bracket 30 carrying pivoted throttle lever 31 which operates the longitudinally movable throttle rod 32 through the medium of links 33. In the form shown, throttle rod 32 is recessed at point 330; receive the extended operating stem 34 of the pilot valve member 29, and in order to insure a seating of the valve head 295 when the valve member is lifted stem 34 carries on its lower end the movable shoe 35 extending beyond the stem 34 and held against the head of the stem by means of spring 36.

As shown in Fig. 1, with the throttle lever in closed position the slice 35 in the recess in rod 32 and valve 29a is closed and will be firmly seated by steam pressure in chamber 27. Under these conditions no exhaust steam is available and there being no pressure in chamber 21, the injector will operate on auxiliary live steam as previously described.

l/Vhen the engine throttle is moved from closed position to admit steam to the engine, pilot valve 29 will not be immediately shifted because the length of recess 33a permits a predetermined movement of the throttle rod before shoe 35 moves out of the recess. The amount of movement of the trottle rod occurring before valve 29 is opened will vary with individual installations, but it will be readily apparent that by suitably proportioning the recess 33a the cuttingofi of the auxiliary sirable under starting conditions, as it per steam supply may be delayed until the throttle is far enough open to insure anadequate exhaust steam supply under all normal operating conditions.

Turning now to Fig. 4; the injector arrangement as shown is substantially the same as shown in Fig. 1 except that in addition to the steam opened exhaust valve 11, a check valve 37 is provided in the exhaust steam conduit 38, said check valve preventing flow from the injector to the engine exhaust pipe. In this form the control system is modified to eliminate the automatic and pilot valves shown in the preceding form; there being substituted a direct auxiliary steam connection from pipe 14 to passage 18 by Way of conduit 39 in which are located a control valve 40 and delay valve 41, the latter-being located between valve 40 and the injector.

As shown in Fig. 6, valve 40 comprises a housing 42 forming inlet chamber 43 and outlet chamber 44, each connected to a branch of conduit 39 and with communication therebetween controlled by valve 40, which is resiliently held to a normal closed position by spring 45. The valve stem 40a extends through a suitable stutling box in housing 42 and the extending end of this valve stem is, as will be seen from Fig. 4, so placed with respect to the throttle operating rod 32 that when the throttle is in closed position, valve 40 is open to admit auxiliary steam to the passage 18. Throttle rod 32 is shouldered as at 32a. and as the throttle is opened the movement of this shoulder past the valve stem permits valve 40 to be closed by spring 45 and held in closed position by steam pressure, thus cutting off the auxiliary steam supply. Obviously the location of the shoulder 32a will determine the closing point of valve 40 with respect to the throttle position and it may be located in a position to insure adequate exhaust steam supply under all conditions before the auxiliary steam is shut ofll.

Because of the elimination of the automatic valve, the exhaust valve can not be controlled in the manner shown in Fig. 1 and in the present form valve 11 is held open at all times when supplementary steam is admit ted to the injector by steam admitted through port 46 placing passage 16 in communication with piston 13. WVith this arrangement the exhaust valve 11 would permit the escape of auxiliary steam through exhaust conduit 38 when the injector is operating on live steam. but such escape of live steam is prevented by the check valve 37.

Valve 41, which is normally seated; by spring 47 is opened by steam pressure in conduit 39 but acts to delay the admission of auxiliary steam to the injector When the latter is started on live steam, this being demits the injector to be primed. bywater and supplementary steam before the auxiliary steam is admitted. This delay valve serves the same function as does the spring 22 in the form shown in Fig. 1, as the latter acts to delay the opening of automatic valveQO so that the injector will receive Water and supplementary steam before auxiliary steam is admitted.

In the form shown in Fig. 4 the necessary pressure reduction of the auxiliary steam may be eflected by making ports 19 in. the

in ector sufliciently small for this purpose.

or it maybe accomplished in other ways, such for example as making conduit 39 of such small sectional area that the pressure drop caused by flow through this conduit effects the necessary reduction in pressure. If deslred, the maximum opening through valve 41 may be regulated so that this valve acts as a choke.

lVhile in accordance with the patent statutes, preferred embodiments of the invention have been illustrated and described,

it will be obvious that many variations and I modifications may be resorted to without departing from the spirit of the invention, the scope of which is to be considered as limited only by the appended claims.

I claim: 1. The combination with an injector utilizing exhaust steam from an engine, of throttle-operating means for controlling steam admission to the engine, and means operatively connected with the throttle-operating means and actuated by movement of the throttle operating means to a predetermined position for causing the admission of an auxiliary live steam supply to the injector.

2. The combinationwith an injector utilizing exhaust steam from an engine, of throttle-operating means for controlling steam admission to the engine, and means for ad mitting auxiliary live steam to the injector when the engine throttle is closed comprising a valve mechanically associated with and actuated by movement of said throttle-operating means.

3. The combination with an injector utilizing exhaust steam from an engine, of throttle-operating means for controlling steam admission to the engine, an automatic valve for admitting auxiliary live steam to the in jecto-r, and a pilot valve controlling said automatic valve, said pilot valve being actuated by movement of the throttle-operating means to and away from closed position.

4. The combination with an injector utilizing exhaust steam from an engine, of throttle-operating means for controlling steam admission to the engine, an automatic valve for admitting auxiliary steam to the injector, said valve being opened by auxiliary steam pressure and closed by the pressure of operating steam acting in opposition to the pressure of the auxiliary steam to overbal- 'ance it, and a pilot valve for admitting said ance it, a pilot valve for admitting said operating steam to the automatic valve, said pilot valve being closed when the throttleoperating means is closed and being opened by the latter when it is moved a predetermined distance it'rom closed position, and means for venting the operating steam from the automatic valve when the pilot valve is closed.

6. The, combination with an injector utilizing exhaust steam from an engine, of throttle-operating means for controlling steam admission to the engine, an automatic valve for admitting auxiliary steam to the injector, said valve being opened by auxiliary steam pressure and closed by the pressure of operating steam acting in opposition to the pres sure of the auxiliary steam to overbalance it, a pilot valve member associated with the throttle-operating means and operated thereby, said member comprising a pilot valve for admitting operating steam to the automatic'valve and a relief valve for venting the operating steam from the automatic valve, said pilot and relief valves opening and closing in alternation and said valve member being arranged to be opened by movement of the throttle-operating mechanism a predetermined distance from closed position.

7. The combination with an injector utilizing exhaust steam from an engine, of throttie-operating means for controlling steam admission to the engine, conduits for admitting to the injector exhaust steam from the engine and auxiliary live steam, steam pressure actuated valves controlling said conduits, said valves acting in alternation in response to the presence or absence of valve operating steam, and means actuated by movement of the throttle-operating means to and away from closed position for controlling said valve operating steam.

8. The combination according to claim in which the means for controlling the valve operating steam comprises a pair of valves opened in alternation by movement of the throttle-operating means to and awayfrom closed position, one ofsaid valves opening to admit operating steam to the control valves and the other of said valves opening to .vent the operating steam from said control valves.

9. The combination with an injector utilizng exhaust steam from an engine, ofthrottle operating means for controlling steam admission to the engine, a conduit for supplying auxiliary steam to the injector, and a control valve in said conduit mechanically associated with and opened by movement of the throttle operating means'to closed position.

10. The combination with aninjector having conduits connected therewith for supplying supplementary steam, auxiliary steam and exhaust steanifrom an engine, of throttle-operating means for controlling steam admissioi'i to the engine, a valve in the auxiliary steam conduit opened by movement of the throttle-operating means to closed position, a valve in the exhaust steam conduit opened by steam from the supplementary steam conduit, and a check valve in the ex haust steam conduit to prevent passage of steam from the injector to the engine when the throttle-operating means is closed.

11. Apparatus of the character described comprising an injector utilizing exhaust steam from an engine, throttle operating means for controlling steam admission to the engine, and, means for admitting auxiliary live steam and exhaust steam to the injector in alternation comprising a valve for controlling the auxiliary steam supply to the injector, said valve having two operative positions, one of which effects admission of auxiliary steam to the injector and the other of which cuts off the auxiliary steam supply and said valve being operatively associated with the throttle operating means so that it is shifted from one to the other of said positions by movement of the latter in a position with the throttle partially open.

12. Apparatus of the character described comprising an injector utilizing exhaust steam from an engine, throttle operating means comprising a throttle rod for controlling steam admission to the engine and mechanism for controlling admission of auxiliary steam to the injector comprising valve means having an operating part contacting said rod, said rod having acam surface thereon operating to shift the position of said valve upon movement of the rod in a position thereof corresponding to partially open position of the throttle.

13. Apparatus of the character described comprising an injector utilizing exhaust steam from an engine, throttle operating means for controlling steam admission to the engine and valve means actuated by movement of the throttle operating means to control admission of auxiliary steam to the inion jector When the throttle is closed, said valve means being arranged to maintain admission of auxiliary steam to the injector until after the throttle operating means is moved to open the throttle a predetermined amount.

JOSEPH F. GRIFFIN. ARTHUR WILLIAMS. 

